The invention relates to honeycomb structures and in particular to methods and apparatus for aligning a body having multiple protrusions with the cells of a honeycomb structure for insertion therein.
Need for the present invention has arisen in the area of fabricating solid particulate filter bodies from honeycomb structures. The honeycomb structures being referred to typically consist of a multiplicity of mutually adjoining and substantially parallel hollow passages or cells which extend through the structure and between a pair of its opposing end faces where the open transverse cross-sections of the cells are exposed. The cells themselves are formed by thin, porous walls which extend continuously between the end faces and intersect with one another so as to form a continuous matrix across the end faces. Solid particulate filter bodies may be formed by selectively manifolding (i.e., plugging) or otherwise selectively sealing different subsets of cells at each of its end faces. Preferred filter bodies of the type being referred to are more completely described in the pending application of Rodney Frost and Irwin Lachman, Ser. No. 165,646, filed July 3, 1980, and now abandoned, entitled "FILTER AND RELATED APPARATUS", which is assigned to the assignee of this application and incorporated in its entirety by reference herein.
One method of selectively manifolding cells is to cover the end faces of the structure with a mask having openings extending through it which expose the open ends of some of the cells at the end face. A suitable material such as a cement is then charged through the mask openings into the exposed cell ends plugging them. One preferred mask embodiment is an elastic mask which in addition to having a number of openings is also provided with a number of elastic protrusions or fingers which fittably engage cells not to be plugged when the mask is aligned over the end face of the structure. The protrusions assure alignment of the openings with the cells and temporarily plug those cells with which they engage to reduce the possibility of their being inadvertently sealed. The elastic mask is more fully described in a pending application Max Montierth, Ser. No. 283,734 filed July 15, 1981, now U.S. Pat. No. 4,411,856, which is assigned to the assignee of this application and incorporated in its entirety by reference herein. As is disclosed in the Montierth application, elastic masks have been hand-fitted to the end faces of honeycomb structures by aligning the mask with an edge of an end face and then working the mask into alignment across the end face. Hand-fitting of masks is time-consuming because the protrusions will generally not engage unless and until they are in precise angular and lateral alignment with the cells, a task made more difficult by the fact that the mask may typically carry hundreds of protrusions.